Calculating device.



R. L. HIBBARD. CALGULATING DEVICE.

APPLICATION FILED AUG. 7, 19'05.

Fbi .1.

PATENTED FEB. l2, 1907.

Figure 1 is a plan view,

UNITED STATES PATENT OlTEiGlE.y

CALCULATING DEVICE.

Application To all whom it may concern:

Be it known that I, ROBERT L. HIBBARD, a citizen of the United States,and a resident of Bellevue, in the county of Allegheny and State ofPennsylvania, have invented a new and useful impro ement in CalculatingDevices, of which the following is a specification. My invention relatesto calculating deviceshand has special reference to devices of the disktype, in which a plurality of annular scales are mounted in a singleplane. -The object of my invention is to provide a disk slide-rule thatshall be simple and inexpensive in construction, effective and accuratein operation, and that shall embody a 'plurality of annular scales allof which are .relatively fixed. Slide-rules or calculating devices ofthe disk type for the continuous calculation of a series of mathematicalprocesses, as heretofore usually constructed, have embodied a pluralityof logarithmic scales one or more of which were movable with respect tothe others. This construction involved a relatively expensive andcomplicated design, since a careful alinement of the fixed and rotatablescales was essential for accurate results, and, furthermore, therotatable scale members were comparatively fragile and subject'toexcessive wear.

Accurate results may readily by the use of the which comprises, ingeneral, a plurality of relatively fixed concentric annular scales and aplurality of transparent disks that are provided with radial index-linesand are rotatably mounted at the common center of the scales. Thisconstruction is especially simple and durable, may be of convenient sizeand shape for transportation, and is relatively inexpensive. l n

Various desirable results, such as the functions of angles and thesquares and square roots of numbers, may by referring from one scale toanother, but the principal advantage in the slide-rule of my inventionlies in the fact that problems be obtained involving the multiplicationand division ofa plurality of numbers may be solved with a minimumnumber of operations, the final result only being read and by referenceto a single stationary scale.

My invention is illustrated in the accompanying drawings, in whichandFig. 2 a par- Specication of Letters Patent.

filed August 7,1905. Serial No. 273,031.

slide-rule of my invention,

be obtained l4 Patented Feb. 12,'1907.

tial section, on a larger scale, of a calculating device constructed in.accordance therewith.

Referring to the drawings, the disk sliderule c comprises a plurality ofconcentric circular scales b, c, d, e, f, and g, a plane basesurface ofany convenient shape, such as the disk JL, a transparent index-arm i,and a transparent disk that are rotatably mounted at thecomnion centerof the aforesaid scales, and an axial member k. The disk 7L isrotatably' mounted on a lower cylindrical portionl of the axial memberand engages a sprin -washer m, which is interposed between t ie disk andan outer flange n on said member. rThe scales may be laid out on thedisk 7i, but a scale-plate 0 is preferably provided, which is so mountedupon the disk that the scales are concentric with the axial member 7c.

The transparent arm i is rotatably mounted upon an upper portion p ofthe axial inem- -ber and is similar to the lower portion, except that itis provided with a cylindrical projection g, which fits into acorresponding -counterbore 1 in the lower member, the transparent arm 'ibeing in engagement with a spring-washer s, that corresponds to thewasher m and separates the disk from an upper fiange which correspondsto the lower flange n, while the transparent disk j is fitted to thecylindrical projection q and is fastened between the two axial members,which are rigidly clamped together by a screw a after the disks areassembled in position. Thus if the disk h upon which the scales aremounted is considered as a stationary element the arm/i and the disk?-are both rotatable relative to each other and to the disk and areprovided, respectively, with radial index-lines i) and w, by whichvalues read on -one scale may be transferred to another scale andvarious mathematical calculations performed, as hereinafter explained.

.it is obvious that the arm i, which rotates in engagement with the diskj, ma),T be replaced by a transparent disksimilar to the disk on whichthe index-line c could be p l until the index-l 28 on the scale.

numbers may be obtained in connection with t e scale c, a scale f forthe natural tangents, a scale g for the natural sines of angles, may bevaried in arrangement and radius of curvature without departingmaterially from the spirit of my invention, and I desire that all suchvariations shall be included within its scope.

To obtain the natural tangent of an angle, one of the radial indices ismoved to correspond to the value of the angle on the scale f, when itsnatural tangent may be read from the scale l). Natural sines may besimilarly obtained by referring from scale g to scale b. The mantissafor common logarithms of numbers may be read from the scale b incombination With the'scale c.

In order to illustrate the cont-inuous multiplication and division ol" aseries of numbers, obtaining a single final result, I will assume aspecific problem The index-line w on the transparent disk y' is set at16 on the scale c. The arm 'fi is then independently moved until theindexline v coincides with. 4 on the same scale. The disk j and theindex-arm t are then both rotated until the index-line e coincides withThe arm 't is then independently moved until the index-line o coincideswith 7, after ine v is coincident with 2, the inal result being' readfrom the position of the index-line w on the scale c. I claim as myinvention`l 1. A calculating device that comprises ya .body portionhaving a plane surface, a plurality of logarithmic scales mountedthereon,

. a transparent disk, having a radial indexline, rotatably mounted onthe plane surface ot the body portion, a second independentlyrotatable,transparent index-bearing memberthat is mounted at the center of thedisk and a two-part clamping device ior said rotatable members;

2. A calculating device that comprises a body -portion having a planesurface, a plurality et scales mounted thereon, a p'aii` of axialclamping-sleeves, a transparent disk and a transparent arm rotatablymounted on the plane surface o f the body portion and clamped inposition relative thereto by said clamping-sleeves.

s 3. A calculating device that comprises a' body portion havinga planesurface;

a plurality of concentric' annular scalesmounted rotatably mountedthereon, apair of 'said axial clamping-sleeves that annular engagingsurfaces are provided with which is lclamped lbetween a transparent disksaid disk being rotatably mounted on one of said portions, and atransparent arm which is on the other bearing.

r l l l l mounted that surfaces, cylindrical bearing portionsl scribedmy name seama- 4. A calculating device that comprises a suitabledisk-shaped body portion, a plurality of relatively fixed, concentric,annular scales mounted thereon, and a pair of axial clamping membersthat are provided with cylindrical engaging surfaces a transparent diskwhich is clamped between said surfaces, said body portion beingrotatably mounted in engagement with said transparent disk and upon acylindrical portion of said axial clamping members.Y

` 5. In a disk slide-rule, .the combination with a suitable body portionthat is provided with plane surfaces, a plurality of relatively fixed,concentric, annular scales mounted thereon, and a pair of axial clampingmembers that are provided with annular engaging surfaces, and atransparent disk that is provided With a radial index-line and isrigidly supported between said clamping-sleeves, said body portion beingrotatably mounted in engagement with said transparent disk and upon acylindrical portion of said axial clamping-sleeves, oitv a secondindependentlyrotatable index that is mounted at the common center.

6. A calculating` device that comprises a suitable body portion that isprovided with a plane surface, a plurality of relatively fixedconcentric, annular, Alo'g r,arithmic scales mounted thereon, atransparent disk and a transparent arm that are rotatably mounted, Withrespectto said body portion, at the common center of said scales and areprovided with radial index-lines.

7. In a disk slide-rule, the combination with a suitable body portionthat is provided with a plane surface, a plurality ol. scales mountedthereon and a pair of axial clamping members that are provided withannular engaging surfaces, and a transparent disk that is provided witha radial index-line and is rigidly supported between said clampingsleeves, said body portion being rotatably mounted in engagement withsaid transpar- `ent disk, of a second independently-rotatable index thatis mounted at the common center.

lOO

IIO

- 8. A calculating device that comprises a disk-shaped portion, a4plurality of' scales mounted thereon, an axial clamping member on Whichsaid body-disk Iis rotatably comprises two similar flanged are providedWith complementary, annular, engaging surfaces, a transparent disk thatuis fixed to said axial member and is provided with a radial index-line, and a second transparentdisk portion that is rotatably mountedon the first and is similarly provided with a radial index-line.

In testimony whereof I have hereunto subthis 3d da` ot August, 1905-.ROBERT L. HIBBARD.

collars which Witnesses:

R. J. DEARBORN. BIRNEY HINEs.

